Abstract
OBJECTIVES: To investigate signal intensity of colorectal cancer liver metastases (CRLM) at hepatobiliary phase (HBP) gadoxetate-enhanced MRI at 2 time points pre- (TP1) and post- chemotherapy (TP2) and association with disease-free survival (DFS) in patients undergoing curative liver resection. METHODS: Retrospective study was conducted. Single largest tumours were outlined and HBP T1 signal intensity was measured and normalized to skeletal muscle at TP1 and TP2. Enhancement thresholds were defined and risk groups at each TP and Kaplan-Meier survival curves were compared using the log-rank test. Univariate and multivariate association of enhancement and 8 clinical features with risk of recurrence were calculated using Cox proportional hazards. RESULTS: 82 patients (48 male, mean age 59 years) underwent 135 imaging studies, 58 at TP1, 77 at TP2, and 53 patients at TP1 + 2. Of 82 patients, 58 recurred with a median time to recurrence of 11.7 months. Enhancement of ≥135 and ≥15 at TP1 and TP2, respectively, were predictive of reduced risk of recurrence (P < .05), although not when corrected for multiple testing (P = .33 and .20, respectively). Enhancement was not associated with recurrence in multivariate model including 8 clinical features (P > .05). Change in enhancement between TP was not associated with risk of recurrence; however, tumours that consistently exhibited low enhancement were 9 times more likely to recur. CONCLUSIONS: Increased CRLM enhancement in the HBP following gadoxetic acid at 2 TPs is associated with improved DFS in patients undergoing liver resection. This initial observation warrants further investigation of serial enhancement measurements as prognostic biomarkers. ADVANCES IN KNOWLEDGE: Dual-time point signal assessment may be informative for clinical outcomes in CRLM undergoing resection.